Insight into why I never remember getting scrapes and bruises

Camping this weekend

My dad: "Do you have a bandaid?"
My mom and I, not even even bothering to ask why anymore: "Here you go"
Dad: "I got cut on that trailor hitch"
Me: "Good grief, you and trailor hitches!"
Dad: "huh?"
Me: "....um, you tore the end of your finger off on one...."
Dad: "oh yeah! I forgot about that! It's numb now, so I don't even think about it..."